The first step towards an Anglo-Norman conquest of Ireland was
made by Henry II of England, who is said to have obtained in 1155
a bull (official document) from Pope Adrian IV authorising him to
take possession of the island, on condition of paying to the papal
treasury a stipulated annual revenue. This bull is thought to have
been a forgery.
In any event, nothing was done until Dermot MacMurrough, the deposed
king of Leinster, sought refuge at Henry's court and obtained permission
to enlist the services of English subjects for a recovery of his
kingdom. Dermot returned to Ireland in 1169 with foreign mercenaries
and numerous Irish allies, and succeeded in recovering part of his
former territories as well as capturing Dublin and other towns on
the east coast. After his death the succession to the kingdom of
Leinster was claimed by his son-in-law Richard Strongbow, 2nd Earl
In 1171 Henry, with a large army, visited Ireland, received homage
from the principal Norman leaders and from the Irish High King,
Rory O'Connor, and granted charters to the Normans authorising them,
as his subjects, to take possession of portions of the island. The
chief Anglo-Norman adventurers, however, encountered formidable
opposition before they succeeded in establishing themselves on the
lands that they claimed. The government was entrusted to a viceroy,
and the Norman legal system was introduced into such parts of the
island as were reduced to obedience to England.
The young Prince John, later King John of England, was sent by
Henry into Ireland in 1185, but the injudicious conduct of his council
provoked disturbances, and he was soon recalled to England. John
made a second expedition to Ireland in 1210 to curb the refractory
spirit of his Norman barons, who had become strong through alliances
with the Irish.
During the 13th century various Anglo-Norman adventurers succeeded
in firmly establishing themselves in Ireland, either by assisting
or suppressing native clans. The Fitzgerald clan acquired power
in Kildare and East Munster; the Le Botiller, or Butler, in West
Munster; and the de Burgh in Connaught.
After the Battle of Bannockburn in 1314, Edward Bruce, the younger
brother of Robert Bruce, King of Scotland, invaded Ireland and attempted
unsuccessfully to overthrow the English there. The pope, at the
instigation of England, excommunicated Bruce and his Irish allies.
Although Bruce's enterprise failed, his invasion highlighted the
decline of English power in Ireland.
The descendants of the most powerful Anglo-Norman settlers in
Ireland gradually became identified with the native Irish, whose
language, habits, and laws they adopted to an increasing extent.
To counteract this, the Anglo-Irish Parliament passed, in 1366-1367,
the Statutes of Kilkenny, decreeing excommunication and heavy penalties
against all those who followed the custom of, or allied themselves
with, the native Irish.
This statute, however, remained inoperative; and although Richard
II later in the 14th century made expeditions into Ireland with
large forces, he failed to achieve any practical result. The power
and influence of the natives increased so much at the time of the
Wars of the Roses that the authority of the English Crown became
limited to the area known as the English Pale, a small coastal district
around Dublin and the port of Drogheda. In the Wars of the Roses,
the struggle in England between the houses of York and Lancaster,
Ireland supported the ultimate loser - the House of York.